"We want to be prepared for the case, particularly given the size of the suggested fine," Sellers said. The amount is believed to be the largest such fine in state history.

State regulators chose such a large penalty because they believe the spill was avoidable. To back up their point, they cite two previous spills from the same sewer main and note that the line was long scheduled for replacement.

Given February's drenching rains--which broke records across the state--city officials call the spill an "act of God." Furthermore, the city attempted to fix the line once during a brief lull in the storms, only to have it break again. The line was largely inaccessible during the rains because the narrow canyon surrounding it was flooded.